Apple Phenolics Protect in Vitro Oxidative Stress‐induced Neuronal Cell Death

Oxidative stress induced by reactive oxygen species may be linked to neurodegenerative diseases. Fresh Red Delicious apples, having 232.9 mg/100 g vitamin C equivalent antioxidant capacity, protected the rat pheochromocytoma neuronal (PC‐12) cells from H 2 O 2 ‐induced oxidative toxicity in vitro in a dose‐dependent manner. MTT (3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5‐diphenyltetrazolium bromide) reduction assay showed significant increase in cell viability when PC‐12 cells were treated with apple extracts. This indicates that the apple phenolics protected oxidative stress‐induced neurotoxicity. Because oxidative stress is also known to increase neuronal cell membrane breakdown, we further investigated by lactate dehydrogenase and trypan blue exclusion assays. Apple phenolics inhibited oxidative stress‐induced membrane damage in neuronal cells. Therefore, these results may suggest that naturally occurring antioxidants, such as phenolic phytochemicals in fresh apples, may reduce the risk of neurodegenerative disorders.